package com.itany.corejava.day07;

public class Test5 {

    public static void main(String[] args) {
        I1 i1=new C1();
        i1.f1();
        ((I2) i1).f2();
        if(i1 instanceof I3) {
            ((I3) i1).f3();
        }

        System.out.println(I1.I);
    }
}
